In optics, an image-forming optical system is a system capable of being used for imaging. The diameter of the aperture of the main objective is a common criteria for comparison among optical systems, such as large telescopes.
The two traditional systems are mirror-systems (catoptrics) and lens-systems (dioptrics), although in the late twentieth century, optical fiber was introduced. Catoptrics and dioptrics have a focal point, while optical fiber transfers an image from one plane to another without an optical focus.
Isaac Newton is reported to have designed what he called a catadioptrical phantasmagoria, which can be interpreted to mean an elaborate structure of both mirrors and lenses.
Catoptrics and optical fiber have no chromatic aberration, while dioptrics need to have this error corrected. Isaac Newton believed that such correction was impossible, because he thought the path of the light depended only on its color. In 1757 John Dollond was able to create an achromatised dioptric, which was the forerunner of the lenses used in all popular photographic equipment today.
Lower-energy X-Rays are the highest energy electromagnetic radiation that can be formed into an image, using a Wolter telescope. There are three types of Wolter telescopes Near infrared is typically the longest wavelength that are handled optically, such as in some large telescopes.
Famous quotes containing the words optical and/or system:
“The convent, which belongs to the West as it does to the East, to antiquity as it does to the present time, to Buddhism and Muhammadanism as it does to Christianity, is one of the optical devices whereby man gains a glimpse of infinity.”
—Victor Hugo (1802–1885)
“Justice in the hands of the powerful is merely a governing system like any other. Why call it justice? Let us rather call it injustice, but of a sly effective order, based entirely on cruel knowledge of the resistance of the weak, their capacity for pain, humiliation and misery. Injustice sustained at the exact degree of necessary tension to turn the cogs of the huge machine-for- the-making-of-rich-men, without bursting the boiler.”
—Georges Bernanos (1888–1948)